This invention relates generally to a multichannel reader for interrogating transponders, and in particular, to a programmable channel search reader or multi-channel reader, which is constructed and arranged to interrogate passive transponders which use different methods of modulation and encoding and different frequencies for their respective communication signals.
Historically, readers and transponders were unique unto themselves. That is, a transponder manufactured by company A could only be read by a reader (transceiver) manufactured by company A. However, as the use of transponders in animals, and more specifically, in pets, became more successful in the marketplace, numerous logistical problems were created as a result of the existence of the different transponders from different manufacturers.
More specifically, different veterinarians were implanting different transponders into pets depending on numerous factors including price, reliability, speed and the like. In this manner, if a pet was lost, a pound or shelter, who found the animal, could read the transponder only with the appropriate transceiver to determine its rightful owner. As a result, numerous transceivers were required to determine the identification of the pet. This process was time consuming and expensive.
Based on this problem, the International Organization for Standards ("ISO") proposed a set of standards for the radio identification of animals ("RFID"), i.e. standards for communication between transponders and transceivers. In its proposed rules, the ISO suggests that a new transceiver be developed that could read all types of transponders and in particular, those within its defined operating range. The ISO flier suggests that a transceiver be developed that accommodates a receiver for each of the respective transponder technologies. Based thereon, a transceiver capable of reading each of the different technologies would be available. Although such a system was never built, such a system would have failed in the marketplace for the following reasons.
First, it would be large in size because it would require a separate receiver for each transponder technology. Second, it would process the information slowly due to the fact that it needed to be read by the different receivers. Third, it would be inflexible because it would be difficult to modify and enhance. That is, it would be difficult to add and subtract different receivers depending on which transponders are used in the particular area of the country or the world. Fourth, it would require a complex antenna arrangement, which would create unnecessary interference among the different antennas.
Accordingly, it is desirable to provide a portable multi-channel reader, which automatically searches for the appropriate channel, is programmable, is capable of reading all types of transponder technologies, is fast-processing and is small in size.